Ridge-furrow with full plastic film mulching improves water use efficiency and tuber yields of potato in a semiarid rainfed ecosystem

A planting pattern of alternate ridges and furrows with plastic film mulching has been viewed as a best management practice for crop production in the arid and semiarid regions, but there is a lack of insight into the underlying changes in soil-crop water relations on mulching areas and ridge-furrow shapes for potato (Solanum tuberosum L.) production. A field study with comparisons of three mulching areas and two ridge-furrow shapes was conducted for two years (2009 and 2010) to assess evapotranspiration, water use efficiency, and tuber yields in the semiarid Northwest China. The experiment included five mulching area and ridge-furrow shape combinations: (1) full mulching on double ridges and furrows (DRFFM), (2) full mulching on both ridges and furrows (RFFM), (3) half mulching only on ridges (RFHM), (4) no mulching on ridges and furrows (RFNM), and (5) traditional-flat planting and without mulching as the control (CK). The two full mulching treatments had the best effect on topsoil temperature-moisture, improved emergence rate by 9.3-14.4% and advanced emergence by 8.1-11.7 days (Pc 0.05). Full mulching treatments reduced evapotranspiration by about 24.0-45.0% during emergence, but increased it by up to 18.7% thereafter, primarily due to rapid increase of LAI under faster development, and also enhanced root/shoot ratio (P < 0.05). Full mulching produced the highest tuber yields (57.4-78.2% higher than the CK) with higher cost of mulching material and labour than the half or no mulching treatments. The full mulching also resulted in the highest water use efficiency (increased by 56.8-70.3% than the CK). The beneficiary effects became smaller with the decrease of mulching areas. However, the difference between the two full mulching treatments was not significant (P > 0.05) despite there was slightly higher WUE in DRFFM than RFFM. Our results revealed that the full mulching on ridge-furrow planting strategy was effective to increase potato productivity and water use efficiency in the semiarid area of Chinese Loess Plateau. (c) 2014 Elsevier B.V. All rights reserved.